The present invention provides an effective and highly scalable mechanism for supporting multiple-request operations (including but not limited to transactions) in a stateless environment, such as the web. A server is used to coordinate the overall processing of client requests. The server performs this coordination function in such a way that: (4) state information associated with multiple-request operations is maintained by the clients making the requests; (5) the clients are unaware that they are maintaining operation-specific state information; and (6) the server itself is not required to persistently maintain the state information, thereby remaining stateless.

Method and apparatus for incorporating state information into a URL

A method of and a system for processing an enterprise application request on an end user application and an application server. This is accomplished by initiating the application request on the end user application in a first language (such as a markup language) with a first application program (such as a Web browser), and transmitting the application request to the server and converting the application from the first language of the first end user application to a language running on the application server, processing the application request on the application server, and transmitting the response from the application server back to the end user application, and converting the response from the language running on the application server to the language of the end user application. The end user application and the application server have at least one connector between them, and the steps of (i) converting the application request from the language of the end user application (as a source language) to the language running on the application server (as a target language), and (ii) converting the response to the application request from the language running on the application server (as a source language) to the language of the end user application (as a target language), each include the steps of invoking connector metamodels of the respective source and target languages, populating the connector metamodels with metamodel data of each of the respective source and target languages, and converting the source language to the target language.

Common application metamodel including c/c++ metamodel

Remote access to objects such as beans is provided by mapping objects onto an HTML page at the network station at which the objects are located. An HTML generator running on the same virtual machine is used dynamically to map the beans onto the HTML page. Remote access for browsing and modifying the object is then possible using a web browser supporting HTTP or HTML protocols without having to specially modify an object to permit access, for example by the provision of remote access code in the object. An application for remote bean access is in the context of a network agent for a network management system.

Method and system for remotely browsing objects

An object-oriented multi-threaded application development system and method for developing resource information software is provided, wherein the application development framework is made up of three tiers. The first tier comprises at least one computer running a web browser, where the web browser is capable of running an object-orientated applet. The second tier similarly comprises at least one computer, wherein the computer runs a web server, a report server, and an application server. The first and second tiers are connected through a network. The third tier comprises at least a third computer, wherein the third computer runs an object-orientated database management system. The third computer is connected to the second tier through a second network.

Distributed, multi-user, multi-threaded application development method

A method and system for processing multiple-request transactions in a stateless environment is provided. A cartridge execution engine intercepts browser messages directed to a cartridge. The cartridge execution engine determines whether the browser messages are associated with transactions. If it is determined that browser messages are associated with transactions, then the cartridge execution engine sends transaction control messages to a transaction manager. In addition, the cartridge execution engine sends operation messages to the cartridge. The cartridge then performs the operations specified in the operation messages. In response to the transaction control messages from the cartridge execution engine, the transaction manager causes the multiple-request transactions to be either committed or rolled back as an atomic unit of work.

Method and apparatus for performing transactions in a stateless web environment which supports a declarative paradigm

We examine several problems related to the preservation of the Independence Principle inheritance. This principle states that all the characteristics of independent superclasses must be inherited by subclasses, even if there are name conflicts. In this context, a conventional approach is to use explicit class selection. We show that this mechanism suffers from serious limitations, and leads to inhibition of refinement and genericity. Our experimental object-oriented language ROME introduces the “Point of View” notion (using an “as-expressions” mechanism) which solves these problems.

The point of view notion for multiple inheritance

The World Wide Web and Distributed Object-Oriented Systems (e.g. CORBA) provide future infrastructures for distributed client/server computing. This paper presents our work to provide the integration of CORBA objects into the Web: first, to describe Web services using object-oriented technologies and second to access any Information System developed with CORBA from the Web. We present a new Shared Information Space model with the following issues: Object Orientation Design, Distributed and Heterogeneous Environment, Users' Point of View, Object Invocation and Navigation. Navigation over SIS is supported by CorbaWeb, a Generic Object Navigator, composed of metascripts allowing the access, the representation and the invocation of any CORBA object from the Web. These operations are achieved by scripts written in CorbaScript, an interpreted scripting language which can dynamically invoke any CORBA objects.

CorbaWeb: a generic object navigator

Aujourd'hui, de nombreux systemes informatiques sont constitues d'applications reparties sur un reseau de type Intranet et au-dela sur l'Internet. La construction, le deploiement, l'execution et l'administration de ces applications reparties necessitent la mise en oeuvre de couches de logiciels intermediaires (appelees aussi « middleware »). Dans ce contexte, la norme Common Object Request Broker Architecture (CORBA) a pour objectif d'offrir un middleware ouvert, bâti sur un modele client/serveur oriente objet. Cette norme est le fruit du travail de standardisation de l'Object Management Group (OMG), un imposant consortium de l'industrie informatique. Cependant, l'effort de l'OMG depasse largement la simple problematique technique du middleware en visant la definition de standards ouverts pour l'integration de logiciels heterogenes et distribues dans tous les secteurs d'activite. La premiere partie de cet article nous mene de la problematique des applications reparties et des middlewares a la vision globale proposee par l'OMG, l'Object Management Architecture (OMA), et les relations avec les solutions concurrentes proposees par le WWW, Java et Microsoft. Ensuite, nous detaillons progressivement les concepts fondamentaux de CORBA, a savoir le modele client/serveur oriente objet, le langage OMG IDL, les composantes du bus d'objets repartis et l'interoperabilite entre bus. Le coeur de cet article etudie concretement et en detail la mise en pratique de CORBA a travers la realisation d'une application repartie ecrite avec les langages de programmation C++, Java et CorbaScript (un langage de script dedie a CORBA). Finalement, nous concluons sur une synthese des apports de l'approche CORBA et decrivons les fonctionnalites attendues dans la prochaine norme CORBA 3.0.

CORBA : des concepts à la pratique

Distributed object computing (DOC) middleware, even if commonly used, has several drawbacks in supporting large and complex distributed applications: no visibility of distributed object interconnections, no implementation separation between business logic and system services, and no application deployment process. In response to this, DOC middleware is evolving to distributed component computing (DCC) middleware such as the Enterprise Java Beans and the CORBA Component Model (CCM). Such middleware provides new solutions to exhibit component interconnections, to separate functional and non-functional aspects, and to deploy components. However, this new middleware generation does not allow applications to have fine-grain control of their deployment process, i.e. the deployment process is hard-coded into DCC middleware and applications cannot adapt it to their requirements. In the context of the CCM, this paper promotes a flexible deployment process supported by a dynamic CORBA Component platform. This platform is composed of an OMG IDL compiler, generic container servers, and our CorbaScript engine (basis and first implementation of the OMG IDLscript specification). It allows software architects to dynamically drive the deployment of their distributed components, as well as to be reactive to their evolutions.

Towards a dynamic CORBA component platform

A system family model (SFM) contains a set of common elements and a set of variable elements known as variation points. Variability modeling is a source of numerous problems: how to express variations, how to ensure the consistency of various views and avoid conflicts. Does the SFM cover all the desired systems? To obtain a specific system, known as "derivation", also known as a product, it is necessary to choose certain variation points from among those included in the SFM model by using a feature model (built during application domain analysis) or a decision model (after SF modelling). The SyF approach presented in this article proposes the "variation point propagation" concept as a means for achieving consistency and dealing with potential conflicts between variations. Under this approach, a decision model, generated from the SFM alone, then enables system family management: analyze coverage of the SF application domain, automate the derivation.

Jean-Marc Geib

Papers

The point of view notion for multiple inheritance

CorbaWeb: a generic object navigator

CORBA : des concepts à la pratique

Towards a dynamic CORBA component platform

Using variation propagation for model-driven management of a system family